A stormwater runoff detention system includes a system including an inlet, a first surge chamber, a second surge chamber and one or more storage chambers. The first surge chamber is connected to receive stormwater from the inlet prior to the second surge chamber or the storage chamber. The first surge chamber includes a discharge outlet and an overflow outlet to the storage chamber. The second surge chamber is connected to receive stormwater from the inlet primarily after the first surge chamber has begun overflowing to the storage chamber. The second surge chamber includes a discharge outlet and an overflow outlet to the storage chamber or to a second storage chamber.